Enterasys Matrix DFE-Gold Series

Enterasys Matrix DFE-Gold Series Configuration Guide 22-1
22
Port Priority and Rate Limiting Configuration
ThischapterdescribesthePortPriorityandRateLimitingsetofcommandsandhowtousethem.
Port Priority Configuration Summary
TheEnterasysMatrixSeriesdevicesupportsClassofService(CoS),whichallowsyoutoassign
mission‐criticaldatatohigherprioritythroughthedevicebydelayinglesscriticaltrafficduring
periodsofcongestion.Thehigherprioritytrafficthroughthedeviceisservicedfirstbeforelower
prioritytraffic.TheClassofService
capabilityofthedeviceisimplementedbyapriorityqueueing
mechanism.ClassofServiceisbasedontheIEEE802.1D(802.1p)standardspecific ation,and
allowsyoutodefineeightpriorities(0 through 7)and,dependingonporttype,upto16transmit
queues(0‐15)oftrafficforeachport.
Apriority0through7
canbesetoneachport,with0beingthelowestpriority.Aportreceivinga
framewithoutpriorityinformationinitstagheaderisassignedapriorityaccordingtothedefault
prioritysettingontheport.Forexample,ifthepriorityofaportissetto4,the
framesreceived
throughthatportwithoutapriorityindicatedintheirtagheaderareclassifiedasapriority4and
transmittedaccordingtothatpriority.
Inaddition,thedevice’sratelimitingcapabilitiesallowyoutofurtherprioritizetrafficbylimiting
therateofinboundoroutboundtrafficonaperport/priority 
basis.
EnterasysNetworks’enhancedCoSimplementationallowsyoutousethefollowingmethodsto
configureClassofServiceontheEnterasysMatrixSeriesdevice:
• Configuringtransmitqueueingandratelimitingonaper‐portbasisasdescribedinthis
chapter.
• Allowingthedevicetoassignpolicy‐basedinboundrateli mitersandtransmit
queuesas
describedinChapter 8.
For information about... Refer to page...
Port Priority Configuration Summary 22-1
Configuring Port Priority 22-2
Configuring Priority to Transmit Queue Mapping 22-5
Configuring Port Traffic Rate Limiting 22-9
Note: When CoS override is enabled using the set policy profile command as described in “set
policy profile” on page 8-3, CoS-based classification rules will take precedence over priority settings
configured with the set port priority command described in this section.